Scientists Warn That Hawaii's Kilauea Volcano Could Erupt 'Ballistic Rocks' : The Two-WayThe U.S. Geological Survey says that as magma in the volcano drops below the water table, it could create steam pressure and a sudden eruption that would spew toxic gas and "ballistic rocks."

Severe ground cracks associated with what's known as Fissure 14 are seen in a burned-out landscape in Leilani Estates near the town of Pahoa, Hawaii, on Wednesday.
U.S. Geological Survey via AP
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U.S. Geological Survey via AP

Severe ground cracks associated with what's known as Fissure 14 are seen in a burned-out landscape in Leilani Estates near the town of Pahoa, Hawaii, on Wednesday.

U.S. Geological Survey via AP

Geologists are warning that Hawaii's Kilauea volcano — which has been belching toxic gas and oozing lava into a residential area for the past week — could erupt explosively in the coming weeks.

The possibility of such a sudden eruption will increase as lava flows from Kilauea's summit crater down its face and magma falls below the water table, the U.S. Geological Survey said. That could create steam pressure that would then explode.

The volcano could then eject "ballistic rocks" of lava up to several feet in diameter, the USGS said.

The Hawaiian Volcano Observatory confirmed Wednesday that a new fissure appeared in Lanipuna Gardens, making a total of 15 such surface cracks where molten lava and gas are escaping, according to Hawaii Public Radio. Lanipuna Gardens, near the town of Pahoa along the island's east coast, is adjacent to Leilani Estates, which has been engulfed in lava.

HPR says no one is being allowed access to Lanipuna Gardens but residents of neighboring Leilani Estates were permitted to go in long enough to retrieve their property.

So far, 36 structures have been destroyed by the lava flow.

Don Swanson, a geologist with the Hawaiian Volcano Observatory, told reporters that the magma is likely to drop below the water table around the middle of the month.

"We suspect it's a rapid process. We really don't know for certain," he told reporters on a conference call.